/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/

/*
 *  PKCS#12 Personal Information Exchange Syntax
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */
/*
 *  The PKCS #12 Personal Information Exchange Syntax Standard v1.1
 *
 *  http://www.rsa.com/rsalabs/pkcs/files/h11301-wp-pkcs-12v1-1-personal-information-exchange-syntax.pdf
 *  ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-12/pkcs-12v1-1.asn
 */

#include "tls/config.h"

#if defined(MBEDTLS_PKCS12_C)

#include "tls/pkcs12.h"
#include "tls/asn1.h"
#include "tls/cipher.h"

#include <string.h>

#if defined(MBEDTLS_ARC4_C)
#include "tls/arc4.h"
#endif

#if defined(MBEDTLS_DES_C)
#include "tls/des.h"
#endif

/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize(void *v, size_t n)
{
	volatile unsigned char *p = v;
	while (n--) {
		*p++ = 0;
	}
}

static int pkcs12_parse_pbe_params(mbedtls_asn1_buf *params, mbedtls_asn1_buf *salt, int *iterations)
{
	int ret;
	unsigned char **p = &params->p;
	const unsigned char *end = params->p + params->len;

	/*
	 *  pkcs-12PbeParams ::= SEQUENCE {
	 *    salt          OCTET STRING,
	 *    iterations    INTEGER
	 *  }
	 *
	 */
	if (params->tag != (MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) {
		return (MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
	}

	if ((ret = mbedtls_asn1_get_tag(p, end, &salt->len, MBEDTLS_ASN1_OCTET_STRING)) != 0) {
		return (MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT + ret);
	}

	salt->p = *p;
	*p += salt->len;

	if ((ret = mbedtls_asn1_get_int(p, end, iterations)) != 0) {
		return (MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT + ret);
	}

	if (*p != end) {
		return (MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}

	return (0);
}

#define PKCS12_MAX_PWDLEN 128

static int pkcs12_pbe_derive_key_iv(mbedtls_asn1_buf *pbe_params, mbedtls_md_type_t md_type, const unsigned char *pwd, size_t pwdlen, unsigned char *key, size_t keylen, unsigned char *iv, size_t ivlen)
{
	int ret, iterations = 0;
	mbedtls_asn1_buf salt;
	size_t i;
	unsigned char unipwd[PKCS12_MAX_PWDLEN * 2 + 2];

	if (pwdlen > PKCS12_MAX_PWDLEN) {
		return (MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA);
	}

	memset(&salt, 0, sizeof(mbedtls_asn1_buf));
	memset(&unipwd, 0, sizeof(unipwd));

	if ((ret = pkcs12_parse_pbe_params(pbe_params, &salt, &iterations)) != 0) {
		return (ret);
	}

	for (i = 0; i < pwdlen; i++) {
		unipwd[i * 2 + 1] = pwd[i];
	}

	if ((ret = mbedtls_pkcs12_derivation(key, keylen, unipwd, pwdlen * 2 + 2, salt.p, salt.len, md_type, MBEDTLS_PKCS12_DERIVE_KEY, iterations)) != 0) {
		return (ret);
	}

	if (iv == NULL || ivlen == 0) {
		return (0);
	}

	if ((ret = mbedtls_pkcs12_derivation(iv, ivlen, unipwd, pwdlen * 2 + 2, salt.p, salt.len, md_type, MBEDTLS_PKCS12_DERIVE_IV, iterations)) != 0) {
		return (ret);
	}
	return (0);
}

#undef PKCS12_MAX_PWDLEN

int mbedtls_pkcs12_pbe_sha1_rc4_128(mbedtls_asn1_buf *pbe_params, int mode, const unsigned char *pwd, size_t pwdlen, const unsigned char *data, size_t len, unsigned char *output)
{
#if !defined(MBEDTLS_ARC4_C)
	((void)pbe_params);
	((void)mode);
	((void)pwd);
	((void)pwdlen);
	((void)data);
	((void)len);
	((void)output);
	return (MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE);
#else
	int ret;
	unsigned char key[16];
	mbedtls_arc4_context ctx;
	((void)mode);

	mbedtls_arc4_init(&ctx);

	if ((ret = pkcs12_pbe_derive_key_iv(pbe_params, MBEDTLS_MD_SHA1, pwd, pwdlen, key, 16, NULL, 0)) != 0) {
		return (ret);
	}

	mbedtls_arc4_setup(&ctx, key, 16);
	if ((ret = mbedtls_arc4_crypt(&ctx, len, data, output)) != 0) {
		goto exit;
	}

exit:
	mbedtls_zeroize(key, sizeof(key));
	mbedtls_arc4_free(&ctx);

	return (ret);
#endif							/* MBEDTLS_ARC4_C */
}

int mbedtls_pkcs12_pbe(mbedtls_asn1_buf *pbe_params, int mode, mbedtls_cipher_type_t cipher_type, mbedtls_md_type_t md_type, const unsigned char *pwd, size_t pwdlen, const unsigned char *data, size_t len, unsigned char *output)
{
	int ret, keylen = 0;
	unsigned char key[32];
	unsigned char iv[16];
	const mbedtls_cipher_info_t *cipher_info;
	mbedtls_cipher_context_t cipher_ctx;
	size_t olen = 0;

	cipher_info = mbedtls_cipher_info_from_type(cipher_type);
	if (cipher_info == NULL) {
		return (MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE);
	}

	keylen = cipher_info->key_bitlen / 8;

	if ((ret = pkcs12_pbe_derive_key_iv(pbe_params, md_type, pwd, pwdlen, key, keylen, iv, cipher_info->iv_size)) != 0) {
		return (ret);
	}

	mbedtls_cipher_init(&cipher_ctx);

	if ((ret = mbedtls_cipher_setup(&cipher_ctx, cipher_info)) != 0) {
		goto exit;
	}

	if ((ret = mbedtls_cipher_setkey(&cipher_ctx, key, 8 * keylen, (mbedtls_operation_t)mode)) != 0) {
		goto exit;
	}

	if ((ret = mbedtls_cipher_set_iv(&cipher_ctx, iv, cipher_info->iv_size)) != 0) {
		goto exit;
	}

	if ((ret = mbedtls_cipher_reset(&cipher_ctx)) != 0) {
		goto exit;
	}

	if ((ret = mbedtls_cipher_update(&cipher_ctx, data, len, output, &olen)) != 0) {
		goto exit;
	}

	if ((ret = mbedtls_cipher_finish(&cipher_ctx, output + olen, &olen)) != 0) {
		ret = MBEDTLS_ERR_PKCS12_PASSWORD_MISMATCH;
	}

exit:
	mbedtls_zeroize(key, sizeof(key));
	mbedtls_zeroize(iv, sizeof(iv));
	mbedtls_cipher_free(&cipher_ctx);

	return (ret);
}

static void pkcs12_fill_buffer(unsigned char *data, size_t data_len, const unsigned char *filler, size_t fill_len)
{
	unsigned char *p = data;
	size_t use_len;

	while (data_len > 0) {
		use_len = (data_len > fill_len) ? fill_len : data_len;
		memcpy(p, filler, use_len);
		p += use_len;
		data_len -= use_len;
	}
}

int mbedtls_pkcs12_derivation(unsigned char *data, size_t datalen, const unsigned char *pwd, size_t pwdlen, const unsigned char *salt, size_t saltlen, mbedtls_md_type_t md_type, int id, int iterations)
{
	int ret;
	unsigned int j;

	unsigned char diversifier[128];
	unsigned char salt_block[128], pwd_block[128], hash_block[128];
	unsigned char hash_output[MBEDTLS_MD_MAX_SIZE];
	unsigned char *p;
	unsigned char c;

	size_t hlen, use_len, v, i;

	const mbedtls_md_info_t *md_info;
	mbedtls_md_context_t md_ctx;

	// This version only allows max of 64 bytes of password or salt
	if (datalen > 128 || pwdlen > 64 || saltlen > 64) {
		return (MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA);
	}

	md_info = mbedtls_md_info_from_type(md_type);
	if (md_info == NULL) {
		return (MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE);
	}

	mbedtls_md_init(&md_ctx);

	if ((ret = mbedtls_md_setup(&md_ctx, md_info, 0)) != 0) {
		return (ret);
	}
	hlen = mbedtls_md_get_size(md_info);

	if (hlen <= 32) {
		v = 64;
	} else {
		v = 128;
	}

	memset(diversifier, (unsigned char)id, v);

	pkcs12_fill_buffer(salt_block, v, salt, saltlen);
	pkcs12_fill_buffer(pwd_block, v, pwd, pwdlen);

	p = data;
	while (datalen > 0) {
		// Calculate hash( diversifier || salt_block || pwd_block )
		if ((ret = mbedtls_md_starts(&md_ctx)) != 0) {
			goto exit;
		}

		if ((ret = mbedtls_md_update(&md_ctx, diversifier, v)) != 0) {
			goto exit;
		}

		if ((ret = mbedtls_md_update(&md_ctx, salt_block, v)) != 0) {
			goto exit;
		}

		if ((ret = mbedtls_md_update(&md_ctx, pwd_block, v)) != 0) {
			goto exit;
		}

		if ((ret = mbedtls_md_finish(&md_ctx, hash_output)) != 0) {
			goto exit;
		}
		// Perform remaining ( iterations - 1 ) recursive hash calculations
		for (i = 1; i < (size_t)iterations; i++) {
			if ((ret = mbedtls_md(md_info, hash_output, hlen, hash_output)) != 0) {
				goto exit;
			}
		}

		use_len = (datalen > hlen) ? hlen : datalen;
		memcpy(p, hash_output, use_len);
		datalen -= use_len;
		p += use_len;

		if (datalen == 0) {
			break;
		}
		// Concatenating copies of hash_output into hash_block (B)
		pkcs12_fill_buffer(hash_block, v, hash_output, hlen);

		// B += 1
		for (i = v; i > 0; i--)
			if (++hash_block[i - 1] != 0) {
				break;
			}
		// salt_block += B
		c = 0;
		for (i = v; i > 0; i--) {
			j = salt_block[i - 1] + hash_block[i - 1] + c;
			c = (unsigned char)(j >> 8);
			salt_block[i - 1] = j & 0xFF;
		}

		// pwd_block  += B
		c = 0;
		for (i = v; i > 0; i--) {
			j = pwd_block[i - 1] + hash_block[i - 1] + c;
			c = (unsigned char)(j >> 8);
			pwd_block[i - 1] = j & 0xFF;
		}
	}

	ret = 0;

exit:
	mbedtls_zeroize(salt_block, sizeof(salt_block));
	mbedtls_zeroize(pwd_block, sizeof(pwd_block));
	mbedtls_zeroize(hash_block, sizeof(hash_block));
	mbedtls_zeroize(hash_output, sizeof(hash_output));

	mbedtls_md_free(&md_ctx);

	return (ret);
}

#endif							/* MBEDTLS_PKCS12_C */
